Two-component polyamide yarns

ABSTRACT

A composite yarn comprising (a) hexamethylene polyadipamide and (b) a ternary copolyamide prepared from hexamethylenediammonium adipate, hexamethylenediammonium terephthalate and an additional salt derived from an aliphatic dicarboxylic acid containing six to 12 carbon atoms and a hexamethylenediamine or a cycloalkane diamine has a latent crimp which can be developed by heat and is particularly suitable for use in the manufacture of hosiery.

United States Patent Grellier et a1.

TWO-COMPONENT POLYAMIDE YARNS Inventors: Rene Grellier, Chavanoz; ClaudeGuyot,

Besancon, both of France Assignee: Societe Rhodiaceda, Paris, FranceFiled: Nov. 24, 1969 Appl. No.: 879,594

Foreign Application Priority Data Oct. 20, 1969 France ..6935853 Nov.25, 1968 France ..175207 U.S.Cl ..161/173,161/175,161/177, 264/171 Int.Cl ..D02g 3/02 I Field of Search ..161/173, 175, 177; 260/78 R;

264/171, DIG. 26

[451 May 23, 1972 References Cited UNITED STATES PATENTS 2,512,6066/1950 Bolton et a1 ..260/78 R 3,393,210 7/1968 Speck 3,526,571 9/1970Ogata "161/175 Primary Examiner-Robert F. Burnett AssistantExaminer-Linda C. Koeckert Attorney-Stevens, Davis, Miller & MosherABSTRACT 7 Claims, No Drawings TWO-COMPONENT POLYAM IDE YARNS Theinvention relates to composite yams comprising two olyamides. Bycomposite yarns are meant yarns of which the constituent filaments havedifferent compositions over different parts of their cross section.

Composite yarns based on at least two polymers having differentshrinkage potentials, their production by simultaneous extrusion of thedifferent polymers through the same holes of a spinneret, and their usein hosiery and in woven fabrics are well known.

The use of composite yarns based on two polymers of the same type ofchemical nature have already been proposed to help overcome certaindisadvantages observed in practice, which result from imperfect cohesionof polymers of difierent chemical nature. Thus the use of yarnscomprising two polyamides fulfilling certain crystallization criteriaand prepared from a homopolyamide, preferably polyhexamethyleneadipamide, and a non-isomorphous copolyamide containing at least 20percent by weight of each of its components one of these preferablybeing hexamethylene adipamide has been proposed. The at least 20 percentby weight of the monomer which gives the final copolyamide itsnonisomorphous properties may optionally consist of a mixture ofmonomers each of which whenused alone would make the polyamidenon-isomorphous. However, due to this introduction of a considerableamount of additional monomer in order to form a non-isomorphouscopolymer, there is a significant difference between the melting pointsof the two polyarnides constituting the composite yarn, and as a resultdifficulties in spinning arise and some of the filaments stick togetherduring winding-up.

Composite yarns based on a homopolyamide and a binary copolyamidecontaining at most 20 percent by weight of nonisomorphous polymer unitsderived from specific diacids and diamines, the remainder consisting ofthe same unit as that of the homopolyamide have also been proposed. Inthis case the melting points of the two polymers are closer together andthe spinning difficulties are considerably reduced. However, there isstill some difference between the melting points and furthermore, whenthe yarns on the spinning bobbin take up moisture, due to the amount ofthe amorphous phase, some filaments of the yarn become stuck together.

The present invention provides a composite yarn which comprises as itspolymer components (a) polyhexamethyleneadipamide and (b) a ternarycopolyamide prepared from hexamethylenediammonium adipate, 5-25 percent(based on the total weight of the salts) of hexamethylenediammoniumterephthalate, and 5-20 percent (on the same basis) of an additionalsalt derived from an aliphatic dicarboxylic acid containing six to 12carbon atoms in the molecule and (i) an unsubstituted or Calkyl-substituted hexamethylenediarnine or (ii) a cycloalkane diamine ofthe formula:

NH RNH wherein R represents (CH2) m (CH2) n R1 R, Ill! or Q I'ti Lwherein m is an integer from 1 to 4, n and n are or integers from 1 to4, p is an integer from 1 to 6, R is H, CH or C H and R is H, CH C H orcyclohexyl.

Where these cycloalkane diamines exsist as structural isomers, they canbe used in the pure form or as an isomer mixture as desired.

Suitable diamine components of the additional salt includehexamethylenediamine, trimethylhexamethylenediamine, 3- aminomethyl-3,5,S-trimethyl-cyclohexylaminel di( 4-aminocyclohexyl)methane and2,2-bis(4-aminocyclohexyl propane. Trimethylhexamethylenediamine isparticularly valuable as a substituted hexamethylenediamine.

Among the aliphatic dicarboxylic acid components of the additional saltadipic, sebacic and dodecanedioic acids may be particularly mentioned,though if the diamine used is hexamethylenediamine the diacid mustobviously be other than adipic acid. 1

The ternary copolyamides can be made by general methods which are wellknown in the art, as can the monomers from which they are made,

The polyhexamethylene adipamide and the ternary copolyamide arepreferably present in the yarn in substantially equal proportions byweight.

This new type of yarn has several substantial advantages due to thepresence of terephthalate units as one of the constituents in theternary copolyamide.

It is found that these yarns are easily spun and also that theindividual filaments do not stick together during cooling, because ofthe very small difference between the melting points of the twoconstituents. Further it is found that these yams do not stick togetherduring winding-up when they take up moisture. In fact, a ternarycopolyamide containing hexamethylene adipamide units, units derived fromhexamethylenediammonium terephthalate, and units derived from anadditional monomer salt which confers nonisomorphous properties on thefinal copolyamide, as described above, can have a higher melting pointthan a binary copolyamide produced from hexamethylenediammonium adipateand an identical proportion of the same additional monomer salt.

The increase in the melt viscosity resulting from the presence of theseadditional monomer units also helps to improve the spinning of the yarn,especially permitting to put the bundle under greater tension. Thisincreased melt viscosity also makes it possible to use a higherviscosity polyhexamethylene adipamide as the other constituent. Thus thecomposite yarns of improved strength may be obtained.

The units derived from hexamethylene diammonium terephthalate in theternary copolyamide enable copolyamides with a high crystallization peakto be obtained and thus the stretching of the yarn to be carried outunder more severe conditions. I

The crystallization peak and the melting peak are measured bydifferential enthalpy analysis, under nitrogen using a temperature riseof 8 C per minute, of a previously melted and quenched sample. Thetemperatures corresponding to the start, the maximum and the end of thecrystallization and melting peaks can thus be observed. The area of thepeak, which is proportional to the degree of crystallization, is givenin the Examples for a weight of polymer of 10 mg.

Finally, the latent crimp of the yarns of this invention is greater thanthat of comparable yarns obtained from binary copolyamides containing noterephthalamide units. The latent crimp can be developed by heating torather high temperatures, but the crimp obtained is more stable topossible temperature variations to which the yarn may be subsequentlysubjected.

The percentage of hexamethylenediammonium terephthalate in thecopolyamide required to confer these properties on the copolymer varieswithin the range of 5 to 25 percent by weight. The advantages obtainedusing copolyamides prepared from less than 5 percent by weight arenegligible while using amounts greater than 25 percent by weight it isdifficult to obtain a copolyamide having a melt viscosity similar tothat of the polyhexamethylene adipamide. [Considerable differencesbetween the melt viscosities of the two constituents of the yarn givesrise to difficulties in spinning]. Preferably, 10 to 15 percent byweight of hexamethylenediammonium terephthalate are used in thepreparation of the eopolyamide. The proportion of units derived from theadditional monomer salt in the eopolyamide varies within the range of 5to 20 percent by weight depending on the desired crimp and on the natureof the additional monomer salt which leads to the non-isomorphouscopolymer used.

The yarns can be obtained by a conventional melt spinning process bysimultaneous extrusion of two polymers, alongside one another or in theform of a non-concentric core and sheath, through the same holes of aspinneret, the ratio of the throughputs rates is preferablysubstantially 1:1 but can be as low as 1/3, to give a ratio ofpolyhexamethylene adipamide to eopolyamide of 1:3 by weight or as greatas 3:1. The yarns so formed are stretched, as by passing them undertension round a snubbing pin, which may be heated, without bringing theyarn to a temperature which would cause appreciable crystallization ofthe copolymer, and the crimp is subsequently developed by heattreatment, for example treatment of the yarn in the tension free stateor of an article produced from the yarn with boiling water. Where theheat-treatment is carried out on a textile article, it mayadvantageously be combined with the dyeing operation.

The crimp obtained is characterized by the extensibility of the yarn andby the half-decrimping and half-recrimping forces. The springiness ofthe crimp and hence its resistance to decrimping is, for a givenextensibility, directly dependent on the magnitude of these forces. Thisresistance to decrimping is important during handling or use of theyarn.

The extensibility is given by the formula:

Wherein L is the length of the decrimped yarn under a load of 225mg/dtex and l is the length of the crimped yarn in a tension-free state.

The measurements may be carried out using an INSTRON tensometer, thecrimp being pulled out and then allowed to return. Graphs are drawn forthe range I to L and the extensibility is read off as the abcissa andthe half-decrimping and half-recrimping forces as the ordinate.

The composite yarns obtained from these ternary eopolyamides andpolyhexamethyleneadipamide may with particular advantage be used inhosiery because of their elasticity and strength and because they impartto the article an attractive appearance and an agreeable feel. They mayalso be used in the manufacture of other knitted fabrics and wovenfabrics and carpets.

The following Examples illustrate the invention.

EXAMPLE 1 Polyhexamethylene adipamide and a eopolyamide produced fromhexamethylenediammonium adipate, hexamethylene-diammonium terephthalateand hexamethylenediammonium sebacate in proportions of 67/17/16 byweight are extruded alongside one another at 290 C, simultaneously in a1:1 weight ratio and at the same throughput, through the same holes of ahole spinneret using a conventional melt spinning device.

On issuing from the spinneret the monofilament yarns travel through anatmosphere of a cooling gas and are then wound up at 420 m/minute.

They are then stretched at ambient temperature in a ratio of 4.12 bybeing passed at a speed of 540 m/minute over a stretching rod 8 mm indiameter. The crimp is developed in boiling water, the yarns being keptin a tension-free state. The yarns then possess the followingproperties:

Gauge (dtex) l7 Tensile strength (g/dtex) 4.45 Elongation at break 36Extensibility 160 Half-decrimping force (mg/dtex) 4.5 Half-recrimping(mg/dtex) 1.8

They are used in the manufacture of stockings having good elasticity andwhich take the shape of the leg well.

EXAMPLE 2 A composite yarn is prepared by the method of Example 1 exceptthat the hexamethylenediammonium sebacate is replaced bydi(4-aminocyc1ohexyl)methane adipate and also the proportions of theconstituents of the eopolyamide being 65/ 1 5/20 by weight.

The two polymers are simultaneously extruded at 292 C through the holesof a 30 hole spinneret, the ratio of the throughputs of thehomopolyamide and of the eopolyamide being 60/40. The resulting yarnsare wound up at 300 m/rninute.

They are then stretched in a ratio of 4.5 by being passed at a speed of3 10 m/minute over a rod heated to 70 C.

After treatment in the tension-free state with boiling water, the yarnspossess the following properties:

Overall gauge (dtex) 550 Tensile strength (g/dtex) 4.45 Elongation atbreak 37.2 Extensibility Half-decrimping force (mg/dtex) l 1.07l-lalf-recrimping force (mg/dtex) 5.85

These yarns are used in the manufacture of carpets by known methods.They show good uniformity and good dyeing affinity.

EXAMPLE 3 Composite yarns are prepared by the procedure of Example 1except that the hexamethylenediammonium sebacate is replaced bydi(4-aminocyclohexyl)methane sebacate, the proportions of theconstituents in the eopolyamide then being 70/15/15 by weight.

The two polymers are extruded at 290 C simultaneously in a 1:1 weightratio and at the same throughput through the holes of a spinneretpossessing three series of 10 holes and the composite yarns obtained arewound up at a speed of 600 m/minute.

They are then stretched at ambient temperature in a ratio of 4.02 bybeing passed at a speed of 470 m/minute over a stretching rod 6 mm indiameter.

The yarns in the tension-free state, are dipped in boiling water todevelop the crimp. They then possess the following properties:

Overall gauge (dtex) 22 Tensile strength (g/dtex) 4.83 Elongation atbreak 32.3 Extensibility Half-decrimping force (mg/dtex) 9.54Halfrecrimping force (mg/dtex) 5.13

The yarns are used for the manufacture of very elastic stockings andhave an attractive appearance on the leg.

EXAMPLE 4 Composite yarns are prepared as in Example 1 except that thehexamethylenediammonium sebacate is replaced by 3-amin0methyl-3,5,5-trimethyl-cyclohexylamine-l adipate, the proportionsof the constituents of the eopolyamide being 75/ 10/15 by weight. Thetwo polyamides are extruded simultaneously in a 1:1 weight ratio and atthe same throughput at 292 C through the same holes of a spinnerethaving two series of 24 holes, and the yams obtained are wound up at aspeed of 600 m/minute.

After being stretched at ambient temperature to a ratio of 3.95 by beingpassed at a speed of 520 m/minute over a rod 6 mm in diameter, the yarnsobtained are dipped in the tensionfree state into boiling water todevelop the crimp. They then have the following properties:

Overall gauge (dtex) 78 Tensile strength (g/dtex) 4.41 Elongation atbreak 34 Extensibility 160 Half-decrimping force (mg/dtex) 1 1.61Half-recrimping force (mg/dtex) 6.75

r EXAMPLE 5 Composite yarns are prepared under the same conditions asdescribed in Example 4, using polyhexamethylene adipamide and acopolyamide produced from hexamethylenediammonium adipate,hexamethylenediammonium terephthalate and di(4-aminocyclohexyl)methaneadipate, in the proportions of 65/15/20 by weight.

After being stretched and treated with boiling water, the yarns have thefollowing properties:

Overall gauge (dtex) 78 Tensile strength (g/dtex) 3.96 Elongation atbreak 32 Extensibility 130 Half-decrimping force (mg/dtex) 13.05Half-recrimping force (mg/dtex) 5.85

EXAMPLE 6 Polyhexamethylene adipamide and a copolyamide produced fromhexamethylenediammonium adipate, hexamethylenediammonium terephthalateand 2,2-bis(4-aminocyclohexyl)-propane dodecanoate (containing 68percent of the trans-trans isomer, 30 percent of the cis-trans isomerand 2 percent of the cis-cis isomer), in the proportions of 70/15/15 byweight, are extruded at 292 C alongside one another, simultaneously in a1:] weight ratio and with the same throughput, through the same holes ofa spinneret possessing two series of 24 holes, using a conventional meltspinning device.

On issuing from the spinneret the yarns travel through an atmosphere ofa cooling gas and are then wound up at the rate of 600 m/minute.

They are then stretched at ambient temperature in a ratio of 3.95 bypassing them at a speed of 520 m/minute over a stretching rod 6 mm indiameter. The crimp is developed by treating the yarns with boilingwater, the yams being kept in a tension-free state. The resulting yarnshave the following properties:

Overall gauge (dtex) 78 Tensile strength (g/dtex) 3.75 Elongation atbreak 3O Extensibility 170 Half-decrimping force (mg/dtex) 8.5Half-recrimping force (mg/dtex) 2.2

EXAMPLE 7 A composite yarn is produced under the same conditions asdescribed in Example 6 except that the 2,2-bis(4-aminocyclohexyl)propanedodecanoate is replaced by 3-aminomethyl-3,5,5-trimethyl-cyclohexylamine-1 adipate, the ratio of theconstituents being 75/15/10 by weight.

The properties of the copolyamide used are summarized in Table I below:

TABLE I (Start 235 Melting peak (C) (Maximum 254 (End 258 (Start 90Crystallization peak (C) (Maximum 93 (End 96 Area of the crystallizationpeak (mm) 465 The crimped yarn obtained after stretching and heattreatment has the following properties:

Overall gauge (dtex) 78 Extensibility 120 Half-decrimping force in(mg/dtex) 10.5 Half-recrimping force in (mg/dtex) 4.1 i

This crimped yarn is of good quality, free of filaments which are stucktogether and the crimp is very regular.

are prepared as described in Example 6 from polyhexamethylene adipamideand a copolyamide produced from hexamethylenediammonium adipate,hexamethylenediammonium terephthalate and a salt of a diacid having sixor 10 carbon atoms and an aliphatic or cycloaliphatic diamine.

The properties of the copolyamides used are summarized in Table 11below:

TABLE 11 Examples 8 9 10 11 Diamine in the additional HexamethyleneS-aminomethylsalt diamine 3,5,5-trimethylcyclohexylamine-l Diacid in theadditional sebacic acid adipic acid salt Percentage by weight ofhexamethylenediammonium terephthalate based on 25 15 5 10 the totalweight of salts Percentage by weight of additional salt based on l5 l5l0 10 the total weight of salts (Start 222 239 241 240 Melting peak (C)(Maximum 242 250 255 254 (End 247 254 258 257 (Start 68 76 81Crystallization (Maximum 73 72 79 84 peak (C) (End 77 82 87 Area of thecrystallization 435 470 475 500 peak (mm After having been stretched andheat treated, the yarns have an attractive crimp and good strength andcan be used for the manufacture of valuable textile articles.

We claim:

1. A composite yarn whose constituent filament or filaments have aside-by-side or non-concentric sheath core structure which consistsessentially of as its polymer components (a) polyhexamethylene adipamideand (b) a ternary copolyamide prepared from hexamethylenediammoniumadipate, 5 to 25 percent (based on the total weight of the salts) ofhexamethylenediammonium terephthalate, and 5 to 20 percent (on the samebasis) of an additional salt derived from an aliphatic dicarboxylic acidcontaining six to 12 carbon atoms in the molecule and a diamine selectedfrom the group consisting of unsubstituted hexamethylenediamines, Calkyl-sub stituted hexamethylene diamines and cycloalkane diamines ofthe fonnula:

Nl-b-R-Nl-l wherein R is selected from the group consisting of (R )n and1 1 R, l 'l l l R1 J.

wherein m is an integer from 1 to 4, n and n are integers from 0 to 4, pis an integer from 1 to 6, R is selected from the group consisting of H,CH and C H and R is selected from the group consisting of H, CH ,C H andcyclohexyl.

2. A yarn according to claim 1, wherein the proportion of units derivedfrom hexarnethylenediammonium terephthalate in the ternary copolyamideis 10 to 15 percent.

3. A yarn according to claim 1, wherein the diamine constituent of thethird component of the ternary copolyamide is sebacic and dodecanedoicacid subject to the proviso that if hexamethylenediamine is used, thedicarboxylic acid is not adipic acid.

6. A yarn according to claim 1, wherein the additional salt is selectedfrom the group consisting of hexamethylenediammonium sebacate,di(4-aminocyclohexyl)methane adipate, di(4-aminocyclohexyl)methanesebacate, S-aminomethyl- 3,5,S-trimethylcyclohexylarnine-l adipate, and2,2-bis(4- aminocyclohexyl )propane dodecanoate.

7. A yarn according to claim 1, containing substantially equalproportions by weight of the polyhexamethylene adipamide and the ternarycopolyamide.

2. A yarn according to claim 1, wherein the proportion of units derivedfrom hexamethylenediammonium terephthalate in the ternary copolyamide is10 to 15 percent.
 3. A yarn according to claim 1, wherein the diamineconstituent of the third component of the ternary copolyamide isselected from the group consisting of hexamethylenediamine,trimethylhexamethylenediamine,3-amino-methyl-3,5,5-trimethylcyclohexylamine-1,di(4-aminocyclo-hexyl)methane and 2, 2-bis(4-aminocyclohexyl)propane. 4.A yarn according to claim 1, wherein the dicarboxylic acid constituentof the third component of the ternary copolyamide is selected from thegroup consisting of adipic, sebacic and dodecanedioic acid subject tothe proviso that if hexamethylenediamine is used, the dicarboxylic acidis not adipic acid.
 5. A yarn according to claim 3, wherein thedicarboxylic acid constituent of the third component of the ternarycopolyamide is selected from the group consisting of adipic, sebacic anddodecanedoic acid subject to the proviso that if hexamethylenediamine isused, the dicarboxylic acid is not adipic acid.
 6. A yarn according toclaim 1, wherein the additional salt is selected from the groupconsisting of hexamethylenediammonium sebacate,di(4-aminocyclohexyl)methane adipate, di(4-aminocyclohexyl)methanesebacate, 3-aminomethyl-3,5,5-trimethylcyclohexylamine-1 adipate, and2,2-bis(4-aminocyclohexyl)propane dodecanoate.
 7. A yarn according toclaim 1, containing substantially equal proportions by weight of thepolyhexamethylene adipamide and the ternary copolyamide.